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ARRL Propagation Bulletin ARLP021 (2016)

ARLP021 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 21  ARLP021
From Tad Cook, K7RA
Seattle, WA  May 20, 2016
To all radio amateurs 

ARLP021 Propagation de K7RA

Average daily solar flux and sunspot numbers rose over the past
week. The average daily sunspot number rose 5 points to 64.1 while
average daily solar flux was up 11.6 points to 100.4. Geomagnetic
indices were quieter, with average planetary A index decreasing from
22.6 to 9.9 and average mid-latitude A index dropping from 14.6 to

USAF and NOAA predict solar flux at 100 on May 20-24, 95 on May
25-26, 90 on May 27-28, 95 on May 29, 100 on May 30 through June 1,
95 on June 2-7, 100 on June 8-9, then 95, 100, and 105 on June
10-12, 100 on June 13-16, 95 on June 17-21, 90 on June 22-24, 95 on
June 25 and 100 on June 26-28.

Predicted planetary A index is 22, 16, 12 and 6 on May 20-23, 5 on
May 24-27, then 15, 25, and 10 on May 28-30, 5 on May 31 and June 1,
12 on June 2-3, then 35, 30 and 15 on June 4-6, 5 on June 7-9, then
8, 15, 25 and 12 on June 10-13, then 8, 18, 25 and 12 on June 14-17,
then 8, 5 and 10 on June 18-20, and 5 on June 21-23.

F.K. Janda, OK1HH of the Czech Propagation Interest Group sends a
weekly geomagnetic activity forecast for the period May 20-June 15,

Geomagnetic field will be: 
Quiet on May 23, 26-27, June 9-10 
Mostly quiet on May 24, June 3, 14-15 
Quiet to unsettled on May 25, 28, June 1-2, 7-8, 11, 
Quiet to active on May 20-22, 29, 31, Jun 4-5, 12-13 
Active to disturbed on May 30, June 6

Increased solar wind from coronal holes is expected on May 22-26,
June 1-2, 6-8, 14-15.

Jeff Hartley, N8II of Shepherdstown, West Virginia sent this report
about what he is hearing in FM19ck.

"It seems like low MUF conditions are here to stay, but 15 M is open
to south EU most days starting around 1400-1500z.

"I operated the 7th Call Area QSO Party on May 7-8 until 0320z on
the 8th. 15 meter activity was way down especially on phone and
propagation was down, but there were solid signals from AZ and NV
from 1600z through past 2130z and all states of the 7th area were
worked during the opening, but the more northern areas MT, ID
(worst), WA and OR were mostly not that loud and in and out, the
peak was around 2000z. My 15M QSO total was 49 versus 167 in 2015,
and SSB was 10 versus 65.

"What was lost on 15 was gained on 20 meters with noticeably less
absorption mid-day due to lower solar flux allowing for more QSOs
but some mobiles were still lost in the noise. Things really started
'cooking' around 1940z through 0100z and I was able to run quite a
few stations on phone and even some on CW. Mobiles were easy copy.
Phone activity did not seem all that high, tuning for stations
calling CQ, but the total tally was 350 20 meter QSOs (my best ever)
versus 258 last year.

"40 meters was affected by the beginning of the solar storm, but not
that badly. I made more QSOs than last year and most stations were
easy copy. It is about 0300z (2300 EDT) before the Sun sets on the
coast of WA at this time of year, so I did not start working OR/WA
until around 0215z. Almost all of the signals, even AZ, sounded
hollow with flutter, but the signal levels were down only slightly
from what I would expect and W7RN in NV was S930 dB without flutter.
Obviously, the K index was high. It was very easy to tell the New
England QSO party W1s from the W7s just by their signal quality. I
did not wait long enough for 80 meters to open well before going
QRT. I operated low power, 150 W.

"Sunday prop was very poor due to the solar storm and that lingered
into Monday with 15M nearly totally dead."

We received a couple of comments from W6ELprop users.

Lloyd Rasmussen, W3IUU of Kensington, Maryland wrote: "I am blind
and use the Window-Eyes screen reader. The text output of W6ELProp
works just fine for me under Windows 7 and 10."

John Leroy, W4JKL of Mount Sterling, Kentucky wrote:

"W6ELProp can be installed and run under Wine for Linux. I run it on
my Debian 8 Jessie box with Wine set to emulate Windows XP. I
installed it on Wine drive_C in the root directory. Once you run an
on-screen path prediction and close the window, you must minimize
the program and then maximize it again to see the menu entries. The
other functions don't require this. The mapping functions work
correctly.  Thanks for reminding me to try this. I normally use
HamCap by VE3NEA under Wine and it works correctly. IonoProbe by
VE3NEA also works correctly under Wine and will feed the latest
online data to HamCap. But another tool is always welcome."

If you would like to make a comment or have a tip for our readers,
email the author at

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at, For an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at More good
information and tutorials on propagation are at

Monthly propagation charts between four USA regions and twelve
overseas locations are at

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bulletins are at

Sunspot numbers for May 12 through 18 were 67, 76, 88, 78, 76, 36,
and 28, with a mean of 64.1. 10.7 cm flux was 92, 93.4, 101.2,
108.4, 102, 103.2, and 102.3, with a mean of 100.4. Estimated
planetary A indices were 4, 8, 10, 13, 13, 13, and 8, with a mean of
9.9. Estimated mid-latitude A indices were 4, 9, 10, 12, 15, 14, and
12, with a mean of 10.9.